/*
 * Converter.java January 2010
 *
 * Copyright (C) 2010, Niall Gallagher <niallg@users.sf.net>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

package wx.xml.simpleframework.xml.convert;

import wx.xml.simpleframework.xml.stream.InputNode;
import wx.xml.simpleframework.xml.stream.OutputNode;

/**
 * The <code>Converter</code> object is used to convert an object
 * to XML by intercepting the normal serialization process. When
 * serializing an object the <code>write</code> method is invoked.
 * This is provided with the object instance to be serialized and
 * the <code>OutputNode</code> to use to write the XML. Values
 * can be taken from the instance and transferred to the node.
 * <p>
 * For deserialization the <code>read</code> method is invoked.
 * This is provided with the <code>InputNode</code>, which can be
 * used to read the elements and attributes representing the
 * member data of the object being deserialized. Once the object
 * has been instantiated it must be returned.
 *
 * @author Niall Gallagher
 * @see wx.xml.simpleframework.xml.convert.AnnotationStrategy
 * @see wx.xml.simpleframework.xml.convert.RegistryStrategy
 */
public interface Converter<T> {

    /**
     * This <code>read</code> method is used to deserialize an object
     * from the source XML. The deserialization is performed using
     * the XML node provided. This node can be used to read the XML
     * elements and attributes in any format required. Once all of
     * the data has been extracted an instance must be returned.
     *
     * @param node this is the node to deserialize the object from
     * @return the object instance resulting from the deserialization
     */
    T read(InputNode node) throws Exception;

    /**
     * This <code>write</code> method is used to serialize an object
     * to XML. The serialization should be performed in such a way
     * that all of the objects values are represented by an element
     * or attribute of the provided node. This ensures that it can
     * be fully deserialized at a later time.
     *
     * @param node  this is the node to serialized to object to
     * @param value this is the value that is to be serialized
     */
    void write(OutputNode node, T value) throws Exception;
}